Technical Field
The disclosed embodiments relate in general to a display apparatus with touch sensor and a method for manufacturing the same, and more particularly to a display apparatus with capacitive touch sensor and a method for manufacturing the same.
Description of the Related Art
Today, electronic products with displays, such as smart phones, tablet personal computers (i.e. tablet PC, flat PC, ex: iPad), laptops, monitors, and televisions, are necessary tools for work and leisure in the daily life. Besides requiring the excellent electrical characteristics of the electronic products such as the higher display quality, faster speed of response, longer useful life and more steady operation state, consumers would also expect more additional functions. Touch panels have been widely used in the applications of portable electronic products, which is a unique interactive viewing screen for the users. Typically, a touch panel is equipped on the front surface of a display apparatus, which allows the user to interact with the device easily; for example, to respond messages by touching the screen at the position corresponding to the query shown on the display, to select listed items on the menu shown on the display, to scroll the listed items, or to provide a free input format such as drawing an object and/or inputting words on the display by handwriting.
A capacitive touch screen is a unique interactive viewing screen which supports multi-touch by gently pinching and provides good experiences for the users (ex: allow pinching and stretching gestures on the screen to control zooming); therefore, the capacitive touch screen has become the commonly use in the consumer electronic products such as smart phones and tablets.
There are a variety of touch screen technologies that have different methods of sensing touch. Based on their driving designs, touch screens can be divided into the following types: resistive touch screen, optical touch screen, capacitive touch screen, and electromagnetic touch screen. A capacitive touch screen is a unique interactive viewing screen which supports multi-touch by gently pinching and provides good experiences for the users (ex: allow pinching and stretching gestures on the screen to control zooming); therefore, the capacitive touch screen has become the commonly use in the consumer electronic products such as smart phones and tablets.
Based on the positions of touch screens, display apparatus with touch sensor can be divided into the following types: out-cell, on-cell and in-cell touch-sensing display apparatuses. The out-cell touch-sensing display apparatus comprises a touch screen stacked on a display panel without touch function. The on-cell touch-sensing display apparatus comprises a touch sensor integrated on the upper surface of a CF substrate. The in-cell touch-sensing display apparatus comprises a touch sensor integrated inside the display panel. Due to the elimination of bulky touch screens attached to the display panels, the on-cell and in-cell touch-sensing display apparatuses, with less glass substrates and thickness of films, have slim appearances and light weight.
FIG. 1A illustrates a display apparatus with touch sensor. The display apparatus 1 with touch sensor comprises a display module 11, a touch-sensing module 13 and a controlling module 15. The touch-sensing module 13 coupled to the display module 11 is disposed in front of the display module 11 to provide a touch-sensitive surface for the user. The controlling module 15 receives signals from the touch-sensing module 13 and provides signals for driving display module 11. FIG. 1B illustrates a conventional capacitive display apparatus having driving electrodes and sensing electrodes. The touch sensing display apparatus typically has multi-touch sensing arrangement to detect and monitor multiple touch attributes (including, for example, identification, position, velocity, size, shape, and magnitude) across the touch sensitive surface 130. A display module of the capacitive touch sensing display apparatus comprises plural sensing electrodes 131 and driving electrodes 133 separated by a non-conductive layer, and the sensing electrodes 131 and the driving electrodes 133 are respectively coupled to the sense circuit 132 and the drive circuit 134. The drive circuit 134 sends driving signals to the driving electrodes 133, and the sense circuit 132 receives multi-touch sensing points provided by the touch sensitive surface 130. In the fabrication, the transparent conductive lines (shaped as rhombus patterns) as the sensing electrodes 131 and the driving electrodes 133 perpendicularly at different layers are formed on an ITO substrate. An object (e.g., finger, stylus, etc.) in contact with or in proximity to touch-sensitive surface 130 can induce the change of the coupling capacitance between the sensing electrodes 131 and the driving electrodes 133, and produce contact patch point (or area). According to the analysis, calculation and process of the controlling module 15, the sensing points on the touch-sensitive surface 130 are mapped into a coordinate system, thereby determining the positions of the contact patch point (or area).
However, the current multi-touch sensing arrangement, as illustrated in FIG. 1B with x-y dual axes of electrodes at driving end and receiving end, takes a long time to complete the driving processing. The driving lines are driven one at a time, while the other driving lines are grounded; this process is repeated orderly from upper to lower or lower to upper until all driving lines have been driven. Positions of touch points on the touch-sensitive surface 130 are determined according to received signals in orders. Once all the lines have been driven, the sequence can repeat to build a series of touch images. This current driving method as described above is a time-consuming processing method.